JP6237479B2 - Battery module and battery pack - Google Patents

Description

  The present invention relates to a battery module and a battery pack in which a plurality of battery cells are arranged in parallel.

  In a battery module in which a plurality of battery cells are arranged side by side, a battery cell and a heat transfer plate that radiates heat generated by the battery cell are arranged in parallel, and heat is radiated by the heat transfer plate. For example, in the battery module described in Patent Document 1, a battery cell group is disposed between a pair of end plates. Between the battery cells constituting the battery cell group, a heat transfer plate bent in an L shape is disposed.

International Publication No. 2013/14517

  By the way, the battery cell expands with use. When the battery cell expands, the heat transfer plate may be deformed by being pressurized from the battery cell. When the heat transfer plate is deformed, the contact area between the battery cell and the heat transfer plate is reduced, and there is a possibility that the heat dissipation performance for the battery cell is lowered.

  The objective of this invention is providing the battery module and battery pack which can suppress the fall of the heat dissipation with respect to a battery cell.

A battery module that solves the above problem includes a plurality of battery cells arranged in parallel and a heat transfer plate that is arranged in parallel to at least one of the plurality of battery cells and radiates heat generated in the battery cells. A battery body, a first end plate and a second end plate that are provided on both sides of the battery cell in the parallel arrangement direction and sandwich the battery body, the first end plate, and the battery body. A battery that is fixed to a member to be fixed, and includes an elastic member that absorbs expansion of the battery cell by elastic deformation and a pressure member that applies a load toward each end plate. The heat transfer plate is adjacent to the battery cell in the juxtaposed direction, and a heat absorption part to which heat generated in the battery cell is transmitted, and from the heat absorption part to the battery cell. Wherein with one of the arrangement direction toward only the second end plate side is extended in contact with the fixed member, the heat dissipation unit for transferring heat transferred to the heat absorbing portion from the battery cell the in the fixed member And have.

  According to this, the end portion (hereinafter referred to as “tip”) in the extending direction of the heat radiating portion faces the side opposite to the elastic member. When the battery cells expand, adjacent battery cells are pressed against each other, and a force directed in the direction in which the battery cells are juxtaposed acts. When this force is applied to the elastic member, the elastic member is elastically deformed. When the elastic member is elastically deformed, the battery cell and the heat transfer plate move toward the first end plate (elastic member). At this time, since the tip of the heat radiating portion does not face the elastic member, even if the heat transfer plate moves toward the elastic member, the tip of the heat radiating portion is not easily caught by the fixed member. For this reason, when the front-end | tip of a thermal radiation part is caught by a to-be-fixed member, it is suppressed that the load from a battery cell concentrates on a heat absorption part, and it is suppressed that the heat absorption part of a heat exchanger plate deform | transforms. For this reason, when a heat absorption part deform | transforms, it is suppressed that the contact area of the heat absorption part of a heat-transfer plate and a battery cell becomes small, and the heat dissipation with respect to a battery cell does not fall easily.

  About the said battery module, it is preferable that the said heat-transfer plate is provided with the connection part which connects the said heat absorption part and the said heat radiating part, and the said connection part is curving so that it may space apart from the said to-be-fixed member.

According to this, when a heat-transfer plate moves toward an elastic member, it is suppressed that a connection part is hooked on a to-be-fixed member.
About the said battery module, it is preferable that the said heat-transfer plate is provided between the said elastic member and the battery cell adjacent to the said elastic member.

  According to this, it is suppressed that the battery cell adjacent to an elastic member contacts an elastic member. Since the elastic member has a lower thermal conductivity than the heat transfer plate, it is easy to dissipate heat generated in the battery cell by providing the heat transfer plate between the battery cell and the elastic member.

  A battery pack that solves the above problem is a battery pack in which the battery module according to any one of claims 1 to 3 is fixed to the fixed member, wherein the fixed member is the battery module. And a heat conductive member provided between the wall member and the heat dissipating part.

  According to this, heat is easily transmitted from the heat radiating portion to the fixed member, and the heat generated in the battery cell is easily radiated to the fixed member.

  ADVANTAGE OF THE INVENTION According to this invention, the fall of the heat dissipation with respect to a battery cell can be suppressed.

The perspective view which shows the battery pack of embodiment. The perspective view which shows the end plate, battery cell, battery holder, and heat-transfer plate of embodiment. Sectional drawing which shows the battery module of embodiment. Sectional drawing which shows the battery module of the state which the elastic member of embodiment elastically deformed. Sectional drawing which expands and shows a part of battery module of embodiment. (A) is sectional drawing which expands and shows a part of battery module of a comparative example, (b) is schematic which shows the state of the heat-transfer plate when the battery cell of the battery module of a comparative example moves.

Hereinafter, an embodiment of a battery pack and a battery module will be described.
As shown in FIGS. 1 and 3, the battery pack BP has a housing 64 as a heat radiator, and the battery module 10 is accommodated in the housing 64. The battery module 10 includes a battery body 11 and a first end plate 12 and a second end plate 13 that sandwich the battery body 11. The battery body 11 includes a plurality of battery cells 20 arranged in parallel and a heat transfer plate 30 arranged alternately in parallel with the battery cells 20. The battery cell 20 is a secondary battery such as a lithium ion battery, for example, and is a square battery. Each battery cell 20 is held by an individual battery holder 40.

  As shown in FIG. 2, the battery cell 20 has an electrode assembly 22 inside a case 21. The electrode assembly 22 has a separator interposed between positive and negative electrodes. The case 21 has a bottomed rectangular box-shaped main body 23 and a lid portion 24 that closes an opening of the main body 23.

  The heat transfer plate 30 is obtained by bending a single metal plate into an L shape. The heat transfer plate 30 includes a rectangular flat plate-shaped heat absorbing portion 31 and a rectangular flat plate-shaped heat radiating portion 32 bent from one end of the heat absorbing portion 31 in the thickness direction of the heat absorbing portion 31. The heat absorbing portion 31 and the heat radiating portion 32 are connected by a connecting portion 33. The connecting portion 33 is a curved portion that is curved in an arc shape formed between the heat absorbing portion 31 and the heat radiating portion 32 by bending a plate material.

  The end plates 12 and 13 are formed by bending a plate material. The end plates 12 and 13 include a plate-like holding portion 14 for holding the battery body 11 and a plate-like fixing portion 15 for fixing the battery module 10 to the housing 64. Have. In the present embodiment, the sandwiching portion 14 has a rectangular shape, and the fixing portion 15 extends from one end in the longitudinal direction of the sandwiching portion 14 in the thickness direction of the sandwiching portion 14. At both end portions in the short direction of the sandwiching portion 14, plate-like insertion portions 18 that project toward the short direction of the sandwiching portion 14 are provided. The insertion portion 18 is provided with an insertion hole 18a penetrating in the thickness direction.

  The battery holder 40 has a rectangular flat plate-shaped first covering wall 41. At both ends in the longitudinal direction of the first covering wall 41, a rectangular flat plate-like second covering wall 42 and a third covering wall 43 extending in the thickness direction of the first covering wall 41 are provided. A region surrounded by the first covering wall 41, the second covering wall 42, and the third covering wall 43 is a housing portion S in which the battery cell 20 is housed. The first longitudinal end portion 42a of the second covering wall 42 (the end opposite to the end portion on which the first covering wall 41 is provided) and the first longitudinal end portion 43a of the third covering wall 43 in the longitudinal direction. A rectangular flat plate-like fourth extending between the first end portions 42b and 43b in the short direction of the respective covering walls 42 and 43 is provided (on the end portion opposite to the end portion on which the first covering wall 41 is provided). The covering wall 44 is provided. The thickness direction of the fourth covering wall 44 coincides with the short direction of the covering walls 42 and 43, and the longitudinal direction thereof coincides with the opposing direction of the second covering wall 42 and the third covering wall 43. The direction perpendicular to the thickness direction and the longitudinal direction of the fourth covering wall 44 is the short direction of the fourth covering wall 44.

  Further, terminals that are U-shaped and open in the thickness direction of the fourth covering wall 44 are formed on one end face in the short direction of the fourth covering wall 44 at both longitudinal ends of the fourth covering wall 44. Each accommodating portion 45 is provided, and each terminal accommodating portion 45 is connected to the second covering wall 42 and the third covering wall 43.

  On one end surface in the short direction of the fourth covering wall 44, a rectangular columnar insertion portion 46 is provided adjacent to the terminal accommodating portion 45. The shaft of the insertion portion 46 extends in the short direction of the respective covering walls 42 and 43. The insertion part 46 is provided with an insertion hole 46 a penetrating in the axial direction of the insertion part 46.

  The longitudinal first end portion 42a of the second covering wall 42 and the longitudinal first end portion 43a of the third covering wall 43 are connected to the covering walls 42, 43. A rectangular flat plate-like projecting wall 47 extending in the longitudinal direction is provided.

  A square columnar insertion portion 49 is provided at the second longitudinal end portion 42 c of the second covering wall 42 and the second longitudinal end portion 43 c of the third covering wall 43. The shaft of the insertion portion 49 extends in the short direction of the respective covering walls 42 and 43. The insertion portion 49 is provided with an insertion hole 49 a penetrating in the axial direction of the insertion portion 49.

  As shown in FIG. 3, the heat absorbing portion 31 of the heat transfer plate 30 is provided in close contact with the battery cell 20. The heat radiating portion 32 of the heat transfer plate 30 covers the surface of the second covering wall 42 in the thickness direction opposite to the surface on the accommodating portion S side. The connecting portion 33 of the heat transfer plate 30 is located on the first end plate 12 side, and the tip 34 of the heat radiating portion 32 of the heat transfer plate 30 (the end portion of the heat radiating portion 32 in the extending direction from the heat absorbing portion 31). Is located on the second end plate 13 side. That is, the heat radiating portion 32 extends from the heat absorbing portion 31 toward the second end plate 13.

  In the battery body 11, the heat transfer plate 30 is located at the end on the first end plate 12 side in the direction in which the battery cells 20 are arranged side by side, and the battery cell 20 is located at the end on the second end plate 13 side. doing. An elastic member 51 is provided between the first end plate 12 and the battery body 11. In the present embodiment, since the heat transfer plate 30 is provided at the end of the battery body 11 on the first end plate 12 side, between the elastic member 51 and the battery cell 20 adjacent to the elastic member 51. A heat transfer plate 30 is provided. The elastic member 51 is plate-shaped, and the thickness direction coincides with the juxtaposed direction of the battery cells 20. As the elastic member 51, rubber, rubber sponge, or the like is used.

  A bolt 61 is inserted into the insertion portion 18 of the second end plate 13 toward the insertion portion 18 of the first end plate 12. The bolt 61 is inserted through the insertion hole 18 a of the second end plate 13, the insertion holes 46 a and 49 a of the battery holder 40, and the insertion hole 18 a of the first end plate 12, and the insertion hole 18 a of the first end plate 12. Is screwed into the nut 62 at a position where the is inserted. Thereby, a restraining load is applied to the first end plate 12 and the second end plate 13 in a direction approaching each other. This binding load is applied to the battery cell 20 and the elastic member 51. Therefore, the bolt 61 and the nut 62 function as a pressure member.

  In the battery module 10 configured as described above, the fixing bolt 63 inserted through the fixing portion 15 of each of the end plates 12 and 13 is screwed into the wall portion 66 of the casing 64 as a wall member. 64 is attached. At this time, the battery module 10 is attached so that the heat radiating part 32 contacts the wall part 66 of the housing 64. Between the wall part 66 of the housing | casing 64 and the thermal radiation part 32, the thermal conduction member (TIM: thermal interface material) 65 is provided. The heat dissipating part 32 is in close contact with the heat conducting member 65 and is in contact with the wall part 66 of the housing 64 via the heat conducting member 65. In the present embodiment, the fixed member is configured by the housing 64 and the heat conducting member 65. Since the connecting portion 33 is curved in an arc shape toward the heat absorbing portion 31, the connecting portion 33 is separated from the heat conducting member 65.

Next, the operation of the battery module 10 of the present embodiment will be described.
When the battery cell 20 is charged and discharged, the heat generated in the battery cell 20 is transmitted to the heat absorption part 31. The heat transmitted to the heat absorbing unit 31 is transmitted to the heat radiating unit 32, and the heat transmitted to the heat radiating unit 32 is transmitted to the housing 64. Thereby, the heat generated in the battery cell 20 is radiated by the heat transfer plate 30.

  As shown in FIG. 4, a film is formed on the electrode of the battery cell 20 with use, and the battery cell 20 expands as the use period becomes longer. When the battery cells 20 expand, the adjacent battery cells 20 are pressed against each other via the heat transfer plate 30. Then, a force directed to both sides in the juxtaposed direction acts on each battery cell 20. The elastic member 51 is elastically deformed and contracted in the thickness direction (parallel direction of the battery cells 20) by this force. Therefore, the elastic member 51 absorbs the expansion of the battery cell 20 by elastic deformation.

  The elastic member 51 is provided between the first end plate 12 and the battery body 11, and the elastic member 51 is not provided between the second end plate 13 and the battery body 11. The battery cell 20 and the heat transfer plate 30 move toward the first end plate 12 (elastic member 51) by elastic deformation.

  As shown in FIG. 5, when the heat transfer plate 30 moves, the tip 34 of the heat radiating portion 32 does not face the moving direction. For this reason, it is suppressed that the front-end | tip 34 of the thermal radiation part 32 is caught by the heat conductive member 65. FIG. Further, since the connecting portion 33 is separated from the heat conducting member 65, the connecting portion 33 is also prevented from being caught by the heat conducting member 65, and the load from the battery cell 20 is concentrated on the heat absorbing portion 31. It is suppressed.

  As shown in FIG. 6A, when the tip 34 of the heat radiating portion 32 faces the moving direction of the heat transfer plate 30, the tip 34 of the heat radiating portion 32 moves to the heat conducting member 65 when the heat transfer plate 30 moves. It is easy to get caught in. Then, the heat conducting member 65 may be damaged, and heat transfer from the heat radiation part 32 to the housing 64 may be hindered.

  Further, as shown in FIG. 6B, when a load from the battery cell 20 is applied to the heat transfer plate 30 with the tip 34 of the heat transfer plate 30 being caught by the heat conductive member 65, the heat transfer plate 30 moves. Since the load from the battery cell 20 is applied in a state where the pressure is regulated, the load from the battery cell 20 is concentrated on the heat absorbing portion 31. Then, the heat absorption part 31 bends with the connection part 33 of the heat transfer plate 30 as a base point. In addition, although exaggerated for convenience of explanation in the figure, since the heat absorbing portion 31 is actually adjacent to the battery cell 20, the bending of the heat absorbing portion 31 is regulated by the battery cell 20 and slightly bent. is there. However, this slight bending reduces the contact area between the battery cell 20 and the heat absorption part 31, reduces the degree of adhesion between the battery cell 20 and the heat absorption part 31, and transfers the heat generated in the battery cell 20 to the heat absorption part 31. It becomes difficult to be done.

Therefore, according to the present embodiment, the following effects can be obtained.
(1) Since the heat radiating portion 32 of the heat transfer plate 30 extends from the heat absorbing portion 31 toward the second end plate 13, the tip 34 of the heat radiating portion 32 faces the second end plate 13. Since the elastic member 51 is provided between the first end plate 12 and the battery body 11, the movement direction of the heat transfer plate 30 when the battery cell 20 expands is on the first end plate 12 side. . For this reason, when the heat transfer plate 30 moves, the tip 34 of the heat radiating part 32 is not oriented in the moving direction, so that the tip 34 of the heat radiating part 32 is not easily caught by the heat conducting member 65. For this reason, when the tip 34 of the heat radiating part 32 is caught, the load from the battery cell 20 is suppressed from being concentrated on the heat absorbing part 31, and deformation of the heat absorbing part 31 of the heat transfer plate 30 can be suppressed. For this reason, it is suppressed that the contact area of the battery cell 20 and the heat absorption part 31 of the heat-transfer plate 30 becomes small, and the heat dissipation with respect to the battery cell 20 does not fall easily.

  (2) The heat absorbing part 31 and the heat radiating part 32 are connected by a connecting part 33. Since the connecting portion 33 is not in contact with the heat conducting member 65, the connecting portion 33 is not easily caught by the heat conducting member 65 when the heat transfer plate 30 moves. Therefore, the heat dissipation with respect to the battery cell 20 is hard to fall.

(3) Since the heat conducting member 65 is provided between the heat radiation part 32 and the housing 64, the heat transmitted from the battery cell 20 to the heat radiation part 32 is easily transmitted to the housing 64.
(4) The heat transfer plate 30 is provided between the elastic member 51 and the battery cell 20 adjacent to the elastic member 51. The elastic member 51 has a lower thermal conductivity than the heat transfer plate 30, and if the elastic member 51 is in contact with the battery cell 20, the heat generated in the battery cell 20 is not easily transmitted to the elastic member 51. By providing the heat transfer plate 30 between the elastic member 51 and the battery cell 20, the heat generated in the battery cell 20 is transmitted to the heat transfer plate 30, so that the heat dissipation performance with respect to the battery cell 20 is unlikely to decrease.

In addition, you may change embodiment as follows.
The heat absorption part 31 and the heat radiation part 32 may be connected without the connection part 33 being interposed. For example, the plate-like heat absorbing portion 31 and the heat radiating portion 32 may be welded, and the heat absorbing portion 31 and the heat radiating portion 32 may be directly connected.

The heat radiation part 32 may be in direct contact with the housing 64. That is, the heat conducting member 65 may not be provided.
The heat transfer plate 30 may not be provided between the elastic member 51 and the battery cell 20 adjacent to the elastic member 51. That is, the elastic member 51 and the battery cell 20 may be in direct contact.

The heat transfer plate 30 may not be provided alternately with the battery cells 20, such as being provided every other battery cell.
A single heat transfer plate 30 may be used.

The heat absorbing portion 31 and the heat radiating portion 32 of the heat transfer plate 30 may be plate-shaped and may be disk-shaped or polygonal-plate shaped.
The pressurizing member may be a metal band that extends from the first end plate 12 to the second end plate 13 and is fixed to the end plates 12 and 13.

  The wall member may be a counterweight mounted on an industrial vehicle.

  BP ... Battery pack, 10 ... Battery module, 11 ... Battery body, 12 ... First end plate, 13 ... Second end plate, 20 ... Battery cell, 30 ... Heat transfer plate, 31 ... Heat absorption part, 32 ... Heat dissipation Reference numeral 33: a connecting part 34: a tip 40: a battery holder 51: an elastic member 61 a bolt 62 a nut 64 a housing 65 a heat conducting member 66 a wall part

Claims (4)

A battery body having a plurality of battery cells arranged in parallel and at least one battery cell among the plurality of battery cells, and a heat transfer plate for radiating heat generated in the battery cells;
A first end plate and a second end plate that are provided on both sides of the battery cells in the juxtaposed direction and sandwich the battery body;
An elastic member provided between the first end plate and the battery body and absorbing expansion of the battery cell by elastic deformation;
A pressure member applying a load in a direction approaching each end plate, and a battery module fixed to a fixed member,
The heat transfer plate is adjacent to the battery cells in the juxtaposed direction, and a heat absorbing part to which heat generated in the battery cells is transmitted, and the second of the juxtaposed directions of the battery cells from the heat absorbing part. A battery module having a heat radiating portion that extends only toward the end plate and contacts the fixed member and transmits heat transferred from the battery cell to the heat absorbing portion to the fixed member. The heat transfer plate includes a connecting portion that connects the heat absorbing portion and the heat radiating portion,
The battery module according to claim 1, wherein the connecting portion is curved so as to be separated from the fixed member.   The battery module according to claim 1, wherein the heat transfer plate is provided between the elastic member and a battery cell adjacent to the elastic member. A battery pack in which the battery module according to any one of claims 1 to 3 is fixed to the fixed member,
The fixed member is a battery pack including a wall member to which the battery module is attached, and a heat conductive member provided between the wall member and the heat dissipation part.